An bidirectional communication system such as a video conference system that transmits images and voices through bidirectional telecommunication via a network is used in various fields.
In recent years, a large number of high-definition large displays are frequently used with enhanced quality of images and voices exchanged in telecommunication via the network, making it possible to perform communication with remote users displayed on the display with realistic feeling.
This bidirectional communication system, however, includes a problem that a line-of-sight direction of a user such as a conference participant displayed on a display unit (display) does not match the direction in which the user actually gazes.
This is because the camera that photographs the user (conference participant) is a photographed image from a certain viewpoint. An image photographed from one camera viewpoint is displayed on a display apparatus on another party.
In a case, however, where there is a viewing user viewing the display image from a direction different from the viewpoint of the camera, the viewing user would feel strange in the viewpoint direction of the user displayed on the display unit.
This problem can be serious particularly in a case where a plurality of users (for example, conference participant) is present in front of the display unit.
In a case where a plurality of viewers is present in front of the display unit, the user at the position corresponding to the position of the camera that photographed the display image on the display unit can observe the image without feeling strange. In contrast, the user existing at a position different from the position corresponding to the position of the camera that photographed the display image on the display unit, the line-of-sight of the other user (conference participant) displayed on the display unit might look completely different from the original situation.
Examples of conventional technologies disclosing a configuration to solve such a problem include Patent Document 1 (Japanese Patent No. 3139100), Patent Document 2 (Japanese Patent No. 3289730), Patent Document 3 (Japanese Patent Application Laid-Open No. 2012-070081), Patent Document 4 (Japanese Patent Application Laid-Open No. 2014-096701), Patent Document 5 (Japanese Patent Application Laid-Open No. 2012-088538), and the like.
The methods disclosed in these conventional technologies, however, include a configuration that requires the use of a special display, a configuration of correcting an eye image of a face included in the image to change the line-of-sight direction, or the like. The configuration using a special display would disable the use of the conventional display, resulting in high cost. In addition, the configuration of correcting the image of the eyes of the face and changes the line-of-sight direction would be a problem such as artificiality to give a strange feeling about the facial expression because the face is partially corrected.